Record wildfires on the West Coast are capping a disastrous decade

With more than a month of fire weather ahead for large parts of the West Coast, the 2020 fire season has already taken a disastrous toll.

Combined, over 5 million acres have burned in California, Oregon and Washington so far. Thousands of buildings have been destroyed by some of the largest fires ever recorded. More than two dozen people have died. Millions up and down the coast have spent weeks living under thick clouds of smoke and ash.

“We’ve broken almost every record there is to break,” said Daniel Swain, a climate scientist at the University of California, Los Angeles, referring to his home state, where catastrophic fires have become an almost-yearly occurrence.

Many fires that erupted in California in August were sparked by lightning strikes, including the August Complex, which has become the state’s largest. It has burned over 850,000 acres — an area larger than Yosemite National Park — in the northern part of the state. The deadly Almeda fire in Oregon is being investigated as possible arson.

But outdated forest management practices and climate change — which brings hotter, drier conditions — have provided the kindling for infernos of such immense scale. Data from two NASA satellites that can detect heat shows that 2020 fire activity on the West Coast has already eclipsed even the worst previous year.

Major fires exploded in California, Oregon and Washington this month, adding up to the worst fire season on record.

In California, some of this year’s largest blazes encroached on areas that had previously burned in recent years, again threatening lives and homes, and putting fragile ecosystems back at risk. The town of Paradise, which was nearly destroyed by the Camp Fire just two years ago, has faced evacuation warnings in recent weeks. Emergency crews are still battling nearby fires, which are among the largest in the state this year.

In Oregon and Washington, fires have burned areas untouched for decades. Several towns have been “substantially destroyed,” according to Gov. Kate Brown of Oregon.

Nearly 20% of fires this year are burning in areas that were scarred by fires as recently as 2000, data from the National Interagency Fire Center shows.

“Reburn,” as Swain called it, can happen after a year or two under “sufficiently extreme climate and weather conditions.” Vegetation that grows back after forest fires may also look differently than what grew before. New growth, including more flammable brush and grasses, could fuel fires and put homes and lives at risk again, he said.

As the climate has warmed, fire season, which traditionally peaks in late summer and into the fall, has been expanding — sometimes starting as early as the spring, and lasting into late fall. Wildfires in the Sierra Nevada region and the Pacific Northwest have also gotten larger and more frequent in recent years.

In the last 20 years, on average, the number of square miles burned annually across California, Oregon and Washington has increased sixfold compared with the average between 1950 and 2000.

Fires have also become more destructive over time, especially as people have moved further into fire-prone areas. A majority of the fires that have destroyed the most buildings and structures have occurred in the past five years, according to a New York Times analysis of state data through the end of last week. Five fires this year are among the most destructive on record.

A look at how air quality has been affected by the wildfires in the west.

The fires this year have not, however, been as deadly as some in the recent past. The Camp Fire, which claimed more than 80 lives in 2018, remains the deadliest in modern California history.

As wind fueled many of the fires in the last month, it also spread a thick blanket of smoke and soot across the region. Far beyond the fire zones, millions of West Coast residents lived under darkened skies and breathed polluted air.

Major cities saw harmful particle pollution known as PM2.5 skyrocket, reaching levels considered dangerous for human health. In Oregon, several cities, including Portland and Eugene, smashed previous daily records for poor air quality during wildfire season.

Breathing in high concentrations of particulate pollution can worsen asthma and other respiratory problems in the short term, and can even lead to strokes or heart attacks. Oregon hospitals reported a 10% increase in emergency room visits for breathing problems during this month’s fires.

Wildfire smoke has also been linked to longer-term consequences, like lower birth weight for babies and impaired lung function in adults.

“Unfortunately, it looks like we’re going to have these occurrences for the foreseeable future,” said Linda George, a professor of environmental science at Portland State University. “Policymakers need to make guidelines for people on how to protect themselves if this is what we’re going to see every summer or every other summer,” she said.

Daniel Jaffe, a professor at the University of Washington who studies the impact of wildfires on air quality, said the only way to reduce the frequency of such “airpocalypse” events was to reduce the frequency of large fires.

“If we could bar people from going into the forests and starting fires, that would help. If we could stop climate change, that would help. Better forest management would help,” he said. “But right now, it combined into the perfect storm.”

© 2020 The New York Times Company